HMF Quiet Core Insert

4.30 out of 5 stars
Fitment Expert:
ATV ATV Utility ATV UTV Make Year Model
HMF Quiet Core Insert
HMF Quiet Core Insert
  • Description
  • Reviews (3)
  • Q&A (11)
  • Fitment
  • HMF Quiet Core Inserts work in all sport series pipes.
  • Simply remove the 3 bolts holding the endcap, swap with the factory spark arrestor, and bolt the cap back on.
  • Reduces noise by about 8-10Db.
4.3 out of 5 stars (3)
4.3 out of 5 stars
5 star   2
4 star 0
3 star   1
2 star 0
1 star 0
See Terms and Conditions
1-3 of 3
Overall 5 out of 5 stars
Ease of Installation
Verified Purchaser
Location: Puyallup, WA, USA
Insert used on trx450er with HMF Performance Seri

Ordered this with HMF Performance Series pipe on my wife's 2006 trx 450er and it performed killer. We got Sound tested by the U.S. Forest Rangers last week at Coos Bay bay. the pipe with the power core insert registered 85db and the limit was 93db at the time. the quad performed really well with this set up after being jetted with the dyno jet kit. it gave real strong performance over stock.

Overall 5 out of 5 stars
Location: Montana
Great product

Just what I was hoping for,quiet for the mountains,easy to pull if need be

Overall 3 out of 5 stars
Location: Pasco, WA
It's quiet

I was on the fence with this purchase, but decided to go for it so I would have it in case I went somewhere with noise regs. In short, I could definitely tell the difference on my 660 Raptor. W/O the quiet core, the Raptor took off like a rocket. With the quiet core, it's still better than stock, but much more sedated. The product is very well made and installs in about 5 minutes. I'd give it more stars if it didn't suck as much power away. Good value for the money.

1-3 of 3
Total Questions (11)
Questions with answers:
Questions without answers:
1-10 of 11
kevin Over 5 months ago
Will this replace the stock baffle?
Have a honda 400ex with a kmf withour baffles will this help
MotoSport Staff Expert
Over 5 months ago
The HMF Quiet Core Insert works with the HMF sport series pipes only. The Stock baffle can be found in the OEM section for your 400EX.
benny Over 5 months ago Location: Dewhurst VIC 3808, Australia
G'day, i have a stock standard LTZ400 2007, will this quiet core insert make a standard muffler even quieter? cheers ben?
Expert MotoSport Staff
Over 5 months ago
It probably would if you could make it fit but the HMF Quiet Core Insert is designed for HMF sport series pipes only.
ajaustin617 Over 7 months ago
Will this fit the bill balance slip on?
Top 1 Contributor
Over 7 months ago
No. This is only for a HMF exhaust.
alex Over 8 months ago Location: Indiana, USA
Will this fit the HMF Performance Series Slip-On Exhaust?
i have performance jetted carbs and i don't know if i have to rejet if i have this because i'm new to all this and i bought my 660 raptor 2 months ago and i already have noise complaints plus I don't know if it fits
MotoSport Staff Expert
Over 8 months ago
Yes. The HMF Quiet Core insert installs on most HMF exhausts in seconds. It's designed for sound sensitive riding areas and decreases the sound level approximately 3-6dB. We recommend re-jetting the exhaust whenever a Quiet Core is installed. Failure to do so can lead to several problems and can damage the exhaust and void the warranty.
Kori Over 9 months ago Location: Ma
How much power will I lose of I use this?
Top 1 Contributor
Over 9 months ago
The internal combustion engine is very simply put a basic air pump. The more air/fuel you can pass through the intake and exhaust from the motor, the more power you will make. HP gains/losses are very subjective to gauge on any one or combination of performance parts. So using a quiet core will cut your power, but WILL allow you to ride if you are in a sensitive noise dB area.
Chris 1 year 5 months ago Location: Suffolk , Virginia
Will this fit the HMF Competition series exhaust?
Expert MotoSport Staff
1 year 5 months ago Location: Portland, OR, USA
Yes, this insert should work with your HMF Competition Series Exhaust on your 2003 Yamaha Warrior 350.
bigjon 1 year 7 months ago Location: Jeanerette, LA 70544, USA
What size is the insert tube outside diameter?
I have a after market muffler on it now with a 1 inch opening too loud in woods needs to quiet down the end is 4 inch dish shaped wondering if this would lip in my muffler
MotoSport Staff Expert
1 year 6 months ago Location: Portland, OR, USA
HMF Quiet Core Inserts work in all HMF sport series pipes. Unfortunately I do not have dimensions on this item. From what I can tell it will only work with HMF Brand Exhaust systems.
moosey Over 5 years ago
This fits "sports series" exhaust but does it fit the hmf utility series?
i have the hmf utility exhaust i ordered off you for a 2007 honda rincon and I just want to make sure the quiet core will fit. thanks Mike
Expert MotoSport Staff
Over 5 years ago
no, sport series only.
quadduner4life10 Over 5 years ago Location: chicagoland
Do you have to rejet the carb after installing?
i got a 2001 honda 400ex the exhaust is great but a little to loud. wondering if i can put this quiet core in without having to rejet the carb again?
MotoSport Staff Expert
Over 5 years ago Location: Portland, OR
You shouldn't have to rejet the quad. More than likely you'll have to adjust the fuel screw.
Michael29 Over 6 years ago
Spark Arrestor?
Does this have a spark arrestor? If not, can you use the HMF spark arrestor & the quiet core both at the same time?
MotoSport Staff
Over 6 years ago Location: Tualatin
No the quiet core does not include the spark arrestor but yes they can be used together
Over 12 months ago Location: Puyallup, WA, USA
No spark arester. I got them to both fit in the HMF performance series pipe and it performed well
1-10 of 11